#ifndef __LIB_DEBUG_H
#define __LIB_DEBUG_H

/* GCC lets us add "attributes" to functions, function
   parameters, etc. to indicate their properties.
   See the GCC manual for details. */
#define UNUSED __attribute__((unused))
#define NO_RETURN __attribute__((noreturn))
#define NO_INLINE __attribute__((noinline))
#define PRINTF_FORMAT(FMT, FIRST) __attribute__((format(printf, FMT, FIRST)))

/* Halts the OS, printing the source file name, line number, and
   function name, plus a user-specific message. */
#define PANIC(...) debug_panic(__FILE__, __LINE__, __func__, __VA_ARGS__)

void debug_panic(const char *file, int line, const char *function,
                 const char *message, ...) PRINTF_FORMAT(4, 5) NO_RETURN;
void debug_backtrace(void);
void debug_backtrace_all(void);

#endif

/* This is outside the header guard so that debug.h may be
   included multiple times with different settings of NDEBUG. */
#undef ASSERT
#undef NOT_REACHED

#ifndef NDEBUG
#define ASSERT(CONDITION)                          \
   if (CONDITION)                                  \
   {                                               \
   }                                               \
   else                                            \
   {                                               \
      PANIC("assertion `%s' failed.", #CONDITION); \
   }
#define NOT_REACHED() PANIC("executed an unreachable statement");
#else
#define ASSERT(CONDITION) ((void)0)
#define NOT_REACHED() for (;;)
#endif /* lib/debug.h */
